The Offensive Weapons Act 2019 (c. 17) is an act of the Parliament of the United Kingdom. The act addresses crimes related to acid attacks (including the sale and possession in public places of corrosive substances); knife crime prevention orders; the sale of, delivery and possession of knives and other offensive weapons; and introduced further restrictions on firearms. It was introduced to Parliament as a government bill by Sajid Javid and Baroness Williams of Trafford of the Home Office.

Restrictions on 0.50 calibre rifles were removed after pressure from members of the European Research Group and the Democratic Unionist Party.

The provisions of the act include:

The bill had its first reading in the House of Commons on 20 June 2018 and its second reading a week later, on 27 June. The bill's committee stage began in July 2018 when it was debated by a public bill committee chaired by Mike Gapes. The committee reported to Parliament on 28 November 2018, with the bill having its third reading the same day.

The bill had its first reading in the House of Lords on 29 November 2018 and its second reading on 7 January 2019. The Lords Committee first debated the bill on 28 January and made its report in February 2019. The bill passed its third reading on 19 March 2019 and the amendments were passed back to the Commons.

MPs amended the Lords' proposals on 26 March and passed the Bill back to the Lords where it was debated on 10 April. The previous Lords amendments which the Commons had refused were not insisted on and the other Commons amendments were accepted. Royal assent was achieved by May 2019.